nestork wrote:
There's been a lot of talk about guns in here lately, and there's
something I've always wondered about...

I don't know how far a regular pistol or rifle will shoot, but this
web site about the battleship USS Missouri (which is the one that
McArther accepted the Japanese surrender on at the end of WWII)

http://en.wikipedia.org/wiki/USS_Missouri_(BB-63)

states as follows:

"Missouri's main battery consisted of nine 16 in (406 mm)/50 cal Mark
7 guns, which could fire 2,700 lb (1,200 kg) armor-piercing shells
some 20 mi (32.2 km)."

20 miles! Geez. Obviously, that's a lot farther than any rifle or
pistol will shoot.

Is that because:

a) the gunpowder used in those cannons is more powerful than the stuff
used in regular bullets,
b) or is it because the battleship's cannons are pointed upward to
maximize range,
c) or is it that the cannon's barrel is longer so the power in the
explosion acts on the projectile for a longer period of time, thereby
accelerating the shell more than a bullet
d) or something else entirely.

It just strikes me as odd. I'm thinking that the ratio of lengths
between a bullet in a rifle barrel and a shell in a cannon barrel
would probably be pretty similar. So, what accounts for the cannon
having 20 times the range? Is it just that the gunpowder used in the
cannon is 20 times as powerful as than that used in bullets, or is it
that the shell stays in it's barrel 20 times longer than a bullet and
therefore receives 20 times as much of a push?

Here's a bullets journal, taken from a Jack Reacher novel:

First thing out of the barrel of Reacher's Barrett was a blast of hot gas.
The powder in the cartridge exploded in a fraction of a millionth of a
second and expanded to a super-heated bubble. That bubble of gas hurled the
bullet down the barrel and forced ahead of it and around it to explode out
into the atmosphere. Most of it was smashed sideways by the muzzle brake in
a perfectly balanced radial pattern, like a doughnut, so that the recoil
moved the barrel straight back against Reacher's shoulder without deflecting
it either sideways or up or down. Meanwhile, behind it, the bullet was
starting to spin inside the barrel as the rifling grooves grabbed at it.

Then the gas ahead of the bullet was heating the oxygen in the air to the
point where the air caught fire. There was a brief flash of flame and the
bullet burst out through the exact center of it, spearing through the burned
air at nineteen hundred miles an hour. A thousandth of a second later, it
was six feet away, and its sound was bravely chasing after it, three times
slower.

The bullet took five hundredths of a second to cross the [parade ground], by
which time the sound of its shot had just passed Reacher's ears and cleared
the ridge of the roof. The bullet had a hand-polished copper jacket and it
was flying straight and true, but by the time it had passed soundlessly over
McGrath's head it had slowed a little. And the air was moving it. It was
moving it right to left as the gentle mountain breeze tugged imperceptibly
at it. Half a second into its travel, the bullet had covered thirteen
hundred feet and it had moved seven inches to the left.

And it had dropped seven inches. Gravity had pulled it in. The more gravity
pulled, the more the bullet slowed. The more it slowed, the more gravity
deflected it. It speared onward in a perfect graceful curve. A whole second
after leaving the barrel, it was nine hundred yards into its journey. Way
past McGrath's running figure, but still over the trees, still three hundred
yards short of its target. Another sixth of a second later, it was clear of
the trees and alongside the office building. Now it was a slow bullet. It
had pulled four feet left and five feet down. It passed well clear of Holly
and was twenty feet past her before she heard the hiss in the air. The sound
of the shot was still to come.

Reacher's bullet hit Borken in the head a full second and a third after he
fired it. It entered the front of his forehead and was out of the back of
his skull three ten-thousandths of a second later. In and out without really
slowing much more at all, because Borken's skull and brains were nothing to
a two-ounce lead projectile with a needle point and a polished metal jacket.
The bullet was well over the endless forest beyond before the pressure wave
built up in Borken's skull and exploded it.

Reacher was watching it through his scope. Heart in his mouth. A full second
and a third is a long time to wait. He watched Borken's skull explode like
it had been burst from the inside with a sledgehammer. It came apart like a
diagram. Reacher saw curved shards of bone bursting outward and red mist
blooming.